(a.) Not stable; not firm, fixed, or constant; subject to change or overthrow.

adrift afloat alternating ambiguous amorphous borderline brittle buoyant canted capricious changeable changeful changing choppy corruptible crumbling dangerous deciduous decrepit desultory deviable deviating deviative deviatory dickey different disintegrating disorderly divaricate divergent diversified diversiform dizzy doubtful dubious dying eccentric effervescent elastic ephemeral erose erratic evanescent fading fast and loose fickle fitful fleeting flickering flighty flitting fluctuant fluctuating fluid fly-by-night flying fragile frail freakish fugacious fugitive giddy hazardous heeling ill-balanced impermanent impetuous impulsive inconsistent inconstant indecisive indefinite infirm insecure insubstantial irregular irresolute irresponsible jagged jerky leaning listing lopsided lubricious mazy mercurial mobile momentary moody mortal motley moving mutable nonconformist nondurable nonpermanent nonstandard nonuniform off-balance overbalanced passing perilous perishable pluralistic poor poorish precarious protean provisional ragged rambling resilient restless risky rocky rootless rotten rotten at rough roving scatterbrained shaky shapeless short-lived shuffling slippery spasmodic spineless sporadic suspect temperamental temporal temporary tentative tergiversating ticklish top-heavy tottery transient transitive transitory treacherous tricky unaccountable unbalanced uncertain uncontrolled undecided undependable undisciplined undurable unenduring unequable unequal uneven unfaithworthy unfirm unfixed unhealthy unorthodox unpredictable unreliable unrestrained unsafe unsettled unsolid unsound unstable as water unstaid unsteadfast unsteady unsturdy unsubstantial unsure unsystematic untrustworthy ununiform vacillating vagrant variable variegated variform various varying vicissitudinary vicissitudinous volatile wandering wanton wavering wavery wavy wayward weak whimsical wishy-washy wobbly